On 2016-07-18 06:41, Drew Adams wrote:
> Even providing a functional-programming definition of `reduce' is
> better than just describing it in abstract terms, if we can't come
> up with a more down-to-earth description.

What about adding a few examples? Something like this maybe?

    (cl-reduce f '(1 2 3 4 5))
      ↔ (f (f (f (f 1 2) 3) 4) 5)

    (cl-reduce f '(1 2 3 4 5) :initial-value 0)
      ↔ (f (f (f (f (f 0 1) 2) 3) 4) 5)

    (cl-reduce f '(1 2 3 4 5) :from-end t)
      ↔ (f 1 (f 2 (f 3 (f 4 5))))

    (cl-reduce f '(1 2 3 4 5) :from-end t :initial-value 0)
      ↔ (f 1 (f 2 (f 3 (f 4 (f 5 0)))))